Feb 1 (Reuters) - Prime Minister Justin Trudeau said on Thursday his government would ensure Kinder Morgan Canada's Trans Mountain oil pipeline expansion is built and added the C$7.4 billion ($6 billion) project is not a threat to Canada's West Coast.

Trudeau reiterated the government's position in two separate radio interviews. His comments came two days after British Columbia proposed new laws that would temporarily ban increased shipments of crude oil through the West Coast province, adding another hurdle to the delayed Trans Mountain expansion project.

"That pipeline is going to get built. We will stand by our decision," Trudeau said in an interview on 630 CHED radio in Edmonton, Alberta. "We will ensure that the Kinder Morgan pipeline gets built."

The Alberta province pledged on Wednesday to sue its western neighbor over the planned legislation, calling on the federal government to step in as it has jurisdiction over inter-provincial infrastructure projects. The federal government approved the expansion in 2016.

Kinder Morgan Canada is pushing to start construction on the Trans Mountain expansion, which will nearly triple capacity on the existing 1,147-kilometer (712 mile) line to 890,000 barrels per day.

"We know that getting our oil resources to new markets across the Pacific is absolutely essential," Trudeau said in a separate interview with CBC Radio, also in Edmonton.

"We can't continue to be trapped with the price differential we have in the American market. We need this pipeline and we're going to move forward with it responsibly like I committed to."

Earlier this month Kinder Morgan delayed the start up of the project, which extends from Alberta's energy heartland to a port in suburban Vancouver, to December 2020, due to continued difficulty obtaining permits.

The project is considered crucial for Canada's oil industry, but is fiercely opposed by British Columbia, many municipalities, some Aboriginal groups, and environmental activists concerned about possible oil spills.

Kinder Morgan Canada's shares were up 0.77 percent at C$16.96 on the Toronto Stock Exchange. ($1 = 1.2282 Canadian dollars) (Reporting by Julie Gordon in Vancouver; Editing by David Gregorio)